摘要:

AbstractThe late fetal and neonatal rat thymus was studied by histological and histochemical techniques following adrenal cortical steriod administration. Albino rats from seventeenth day of gestation through thirtieth postnatal day were sacrificed six, 24, 48 and 96 hours following single or series of cortisone or hydrocortisone injections in pregnant or neonatal rats. Some of gestation periods were prolonged by progesterone injections. Stains included Harris hematoxylin and eosin, May‐Grünwald Giemsa, Gomori's ('52) or Burstone's ('58) method for alkaline phosphatase, and the PAS stain. Autofluorescence was examined in some of the sections.A reduction in distinctness of the cortico‐medullary border of the fetal thymus followed maternal cortical steriod treatment. Similar treatment in neonatals one and two days of age led to pycnosis and phagocytosis of small lymphocytes. No histochemically stainable alkaline phosphatase was observed before sixteenth postnatal day, or following steriod administration on day one or two. However, a precocious increase in alkaline phosphatase followed a single injection on day 12. In the fetal and neonatal thymus PAS‐positive material was present, was more prominent on the sixteenth day, and increased following steriod treatment, particularly on the twelfth day. Autofluorescent cells, present on the sixteenth day, increased following steriod administration. Histochemical and autofluorescent modifications were particularly prominent at the cortico‐medullary border and are thought to represent postnatal maturation about the sixteenth day which changes can be induced precociously by cortical

ISSN:0003-276X    

DOI:10.1002/ar.1091570202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractThe concentrations of LH and FSH were measured in the blood and adenohypophyses of castrated male rats exposed to high levels of testosterone propionate for 1 to 18 weeks. In intact male and female rats, similarly treated for 1 to 5 weeks, blood levels could not be measured but pituitary hormone levels were. Histological study of the pituitary gonadotrophic cells of all groups revealed a striking correlation between their regression, in response to androgen treatment, and the decline in pituitary LH stores. No light‐microscopic correlate of the marked, progressive increase in pituitary FSH concentration was detected. Thus, when the pituitary FSH:LH ratio had increased 90 fold, all gonadotrophs appeared inactive.Although these studies failed to reveal the specific cellular source(s) of FSH and LH, they did clarify several aspects of the dynamics of the pituitary secretory responses to orchidectomy and androgen treatment. In the light of this information, the suggestion is made that the greatest dichotomy between pituitary FSH and LHstoresis not coincident with — and probably occurs later than — that between LH and FSHsecretion. Such asynchrony between the various phases of the FSH and LH secretory responses to these treatments (castration and/or androgen administration), may explain several seeming discrepancies among earlier reports on this su

ISSN:0003-276X    

DOI:10.1002/ar.1091570203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractPrevious studies have shown that pentobarbital administration at 2 p.m. of proestrus in the rat blocks ovulation and the drop in pituitary LH content normally seen at estrus; these data were interpreted as indicating that the drug acted by blocking LH release. Signs of prolongation of estrogen secretion were seen in these rats and, in the absence of further treatment, ovulation occurred 24 hours later. In the present study a single dose of anti‐ovine‐LH‐serum administered at 1 p.m. of proestrus also blocked ovulation, but did not prevent the drop in pituitary content on the moring of “estrus.” Therefore, one may conclude that this blockade was the result of preventing the peripheral effects of LH on the ovary. The antiserum blockade did not produce prolongation of estrogen secretion and no rat ovulated within the next four days. During this time pituitary LH content was normal, as were ovarian and uterine weight, although large follicles, rather than recent corpora lutea, were seen in the ovary. Six rats were followed until the next vaginal cornification (by 6 days); only three of the six had ovulated by day seven. The contrast between the sequelae of pentobarbital and antiserum blockade is interpreted in the light of a new theory of regulation of reproductive cyclicity i

ISSN:0003-276X    

DOI:10.1002/ar.1091570204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractThe sexual behavior scores of three different groups of DBA/2J male mice, run at different times of the year, in two different places, and by different observers, were compared. Of 46 comparisons, two revealed statistically significant differences. It was hypothesized that one measure (% Move) was subject to much environmentally determined variation, while for the other measure (III), the significant difference may have been due to sampling error.Furthermore, substitution of the data resulting from either replication for the data of the DBA/2J males of the original study did not result in any changes as regards significant differences in sexual behavior among DBA/2J, C57BL, and BALB/c male mice. The results, in general, supported the hypothesis that intensive study of a small sample from an inbred strain would yield replicable results.

ISSN:0003-276X    

DOI:10.1002/ar.1091570205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractGroups of 10 to 14 castrated female BALB / c mice received viable uni‐ or bilateral intraocular isografts of one‐eighth or of one‐thirty‐second of an ovary. Ten other animals remained intact. At biopsy five months later, the mammary glands of all animals showed little or no stimulation. Most animals with one or two one‐eighth or two one‐thirty‐second, grafts had shown normal vaginal and ovarian cycles prior to this time, but some had been in continuous metestrus and had acyclic grafts with vesicular follicles. Most animals with one one‐thirty‐second grafts were similarly in metestrus, but some were in diestrus with grafts lacking follicular structures. At autopsy eight months after grafting, almost all mice with one or two one‐eighth grafts had alveolar proliferaiton with secretion in the mammary glands. All were in continuous metestrus with acyclic grafts, and most had uterine cystic hyperplasia and peri‐medullary adrenal degeneration. At the same time, slightly more and slightly less than a half of the mice with one or two one‐thirty‐second grafts, respectively, showed these same abnormalities. Intact mice were devoid of them. The development of this mammary‐uterine‐adrenal syndrome appeared to be directly related to grafted ovarian tissueper seand to the size of the grafts. It may depend upon a pituitary‐ovarian imbalan

ISSN:0003-276X    

DOI:10.1002/ar.1091570206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractThe effect of exogenous estrogen on tubal transport of ova was determined in the guinea pig, hamster, mouse, rabbit and rat. The animals were given a single injection of estradiol cyclopentylpropionate (ECP) shortly after mating. The dose of ECP required to interrupt pregnancy in 80% or more of the animals was as follows: guinea pig (10 μg); hamster (25 μg); mouse (1 μg); rabbit (50 μg); rat (10 μg). Acceleration of egg transport through the oviduct occurred after the following doses of ECP: guinea pig (50–100 μg); hamster (100 μg); mouse (1 μg and above); rabbit (25 μg); rat (10 μg and above). Hence, the amount of estrogen which accelerates egg transport in the guinea pig and hamster is considerably higher than the dose which interrupts pregnancy.Retentionof ova for longer than the normal period of tubal passage (tube‐locking) resulted from the following doses of ECP: guinea pig (250 μg); hamster (250 μg); mouse (1 μg); rabbit (100 μg); rat (no dose). In the species in which ova were tubelocked, the majority of eggs were located at the ampullary‐isthmic junction rather than the utero‐tubal region of the oviduct.Tube‐locking of ova was never observed in the rat; ECP always caused premature entry of eggs into the uterus and eventual expulsionper vaginam. For example, eggs passed through the cervix by 12 hours after the administration of 250 μg E

ISSN:0003-276X    

DOI:10.1002/ar.1091570207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractTo investigate the role of gonadal hormones during the postnatal period on the development of masculine and feminine behavior 129 male and female rats were hormonally manipulated at birth. Within 24 hours of birth male and female rats were: (a) sham operated, (b) gonadectomized, (c) gonadectomized and given testosterone, or (d) gonadectomized and given estrogen. When adult all animals were given testosterone and tested for the display of male behavior, and then given estrogen and progesterone and tested for female behavior. Male behavior: Males exhibited mounting responses more frequently than females regardless of hormone manipulation at birth. Androgen and estrogen at birth did not facilitate mounting behavior in either sex. Males exhibited more frequent intromission responses than females. Animals treated with androgen at birth showed more frequent intromission behavior than non‐treated animals. Androgen facilitated intromission relatively more in males than in females. Estrogen at birth did not facilitate intromission behavior. Female behavior: Males castrated at birth, normal females, and females ovariectomized at birth showed high levels of receptivity. No other animal exhibited frequent lordosis. The data indicated that behavioral sexual differentiation induced by hormones in in‐fancy is best characterized by an inhibition of the potential to display feminine behav

ISSN:0003-276X    

DOI:10.1002/ar.1091570208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractPrepubertally castrate female rats are capable of showing the lordosis response when given replacement therapy with female sex steroids, regardeless of age at which the ovaries are removed post birth, or when replacement therapy is commenced after adulthood. Estrogen alone is reraly a sufficient stimulus for behavioral estrus. Therefore the natural physiological trigger for estrous behavior in the rat is likely estrogen plus progesterone. Prepubertally castrate male or female rats never showed any male or female behavior following androgen implant in the brain. All rats castrated on day three or ealier, and given implants of estrogen plus progesterone in the preoptic hypothalamic area displayed the lordosis response. Thus the female sex response pattern is present in both sexes in the absence of gonadal hormones from birth. Brain development in the male castrate at birth does not appear to be identical to brain development in the female castrate at birth because a number of males showed the complete male sexual response pattern plus the female response pattern following neural implant of estrogen plus progesteron. The genotypic male thus appears to possess the information necessary to produce the neural connections for male and female sexual response patterns. Androgen acting at birth disrupts the development of the feminine response pattern so that the adult male ordinarily displays only the copulatory pattern.

ISSN:0003-276X    

DOI:10.1002/ar.1091570209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractHistological characteristics of testis tissues from 25 African elephants (Loxodonta africana) collected in Uganda, showed no consistent relationships among the following variables: Leydig cell size, cytoplasmic characteristics, and abundance; testicular testosterone content; and age. From these findings, plus field observations of sexual behavior, emerges the hypothesis that individual cyclicity in Leydig cell function was inherent in the elephant population studied. Testosterone content of testes from 32 elephants (including the 25 studied histologically) suggested that lone bulls were not of a senile nature since they contained relatively large quantities of testosterone and were relatively young (from about 12 to 25 years of age). Also, lone bulls were observed searching out estrous females. Among bulls collected from family units and herds, testosterone levels and behavior differed conspicuously. Behavior appeared to be directly related to testosterone content in several instances. Nonaggressive behavior among members of bull herds, plus the high proportion of such aggressive behavior among members of bull herds, plus the high proportion of such individuals with low testosterone content, suggest that some of these animals were in a depressed phase of sexual activity whereas others were undergoing pubertal development.

ISSN:0003-276X    

DOI:10.1002/ar.1091570210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091570211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY